Working on merge: changed the way that we handle kernels in the AST and SimpleAST IRs (treat
them like literals, instead of like variables). Added code to rewrite Inside tests in Simple
IR to use the image instead of the field, which fixes a problem with trying to do inside tests
on Ein fields. Added code to promote locals to globals as part of the simplify-vars phase.

Modify compiler to dynamically determine the intall location of the Diderot
libraries and include files. This feature will allow the diderot compiler
to be installed in places other than where it is built.